Spirit level



Sept- 4, 1951 T. F. vAlDA 2,566,542

SPIRIT LEVEL` Filed sept. 5, 194e f4 ff /7 Tijd.. #M

MIMMIHMIUIWN III" y u" T. BY @my @n Patented Sept. 4, 1951 UNITED STATES` PATENT FFICE SPIRIT LEVEL Theodore F. Vada, High Bridge, N. J.

Application September 5, 1946, Serial No. 694,925

1 Claim. l

This invention relates to spirit levels or the like embodying the advantages inherent both to Wooden and metallic-bodied levels of this character.

Principal objects of the invention are to provide durable levels constructed both of wood and of metal which are highly resistant to wear, lighter in weight than an all metal level, nonwarping and highly resistant to breakage.

A further object of the invention is to provide levels that are simple in construction and which may be manufactured simply and at comparatively low cost.

To the accomplishment of the foregoing and such other objects as may hereinafter appear, this invention consists in the novel construction and arrangement of parts hereinafter to be described and then sought to be defined in the appended claim, reference being had to the accompanying drawing forming a part hereof, which shows, merely for the purposes of illustrative disclosure, a preferred embodiment of the invention, it being expressly understood, however, that changes may be made in practice within the scope of the claim Without digressing from the inventive idea.

In the drawing, wherein similar reference characters denote corresponding parts:

Fig. l is an elevational view of a level embodying the invention Fig. 2 is an enlarged partial vertical elevation with portions broken away to show structural details;

Fig. 3 is a vertical section taken along line 3 3 of Fig. 2;

Fig. 4 is a longitudinal vertical section taken along line 4-4 of Fig. 3;

Fig. 5 is a vertical section taken along line 5-5 of Fig. 2; and

Fig. 6 is a fragmentary perspective view showing further structural details.

Referring to the drawing, lil denotes the level. This level comprises a metal core or ply I of cast aluminum or other metal and consisting of segments I2 and I3 joined end to end, for example, by the dovetail joints I4. These segments I2, I3 have substantially I beam sections and are provided with opposite outer flanges |2a, |3a and with aligned longitudinally oppositely-extending reinforcing ribs |21), |319. The segments I2 are each provided with a large hole I5 dened by the oppositely extending lateral annular anges I6, I'l. Abutments I8 integral with the segments I2 extend inwardly of the opening I5 at diametrically opposite points and serve for mounting of one or more leveling fluid-containing vials I9, 20 as will be presently described.

Wooden facing members or plies 2|, 22 are secured permanently to the opposite faces of the joined segments I2, I3. These Wooden facing members 2 I, 22 originally are of somewhat greater dimensions than the segments I2, I3. The internal faces of these members 2|, 22 have longitudinal grooves 23, 2li, 25 and 26 admeasured to receive respectively the ribs |217, |319 and the outer flanges I2a, IBa so that in effect these internal faces are complemental in shape with the respective outer side faces of the segments I2, I3. The wooden facing members 2|, 22 also have holes 21, 28 admeasured in diameter to fit snugly around the lateral flanges, I6 and il.

In assembling the parts so far described, suilicient of the segments I2, I3 are joined end to end by interengagement of their dovetail joint parts I4 to constitute the desired level length. The opposite ribbed side surfaces of these segments are then coated with an adhesive resin, hereinafter to be described. The internal, grooved faces of the wooden facing members 2 I, 22 of desired length then have an adhesive undercoating resin presently to be described applied thereto, and an overcoat of the first-mentioned resin. The so coated facing wooden members or plies 2|, 22 are then fitted and applied to the opposite ribbed surfaces of the resin coated segments l2, I3 and the intertted parts are forced intimately together under heat and pressure to bond the parts permanently together on their resin-coated surfaces. The resin bonds are permanent, Very strong, and the resultant ply structure consisting of an inner metallic ply or core sandwiched between. outer wood plies or layers 2|, 22 is very strong and not liable to deformation. Likewise the resin bonds hold rmly under Varying atmospheric conditions.

When the wooden plies 2 I, 22 and inner metallic ply or core I I have rbeen bonded together as described, the wooden layers or plies 2|, 22 are trimmed or ground flush with the outer surfaces of the metallic ply and the bottom surfaces of the combined plies ground smooth and flush to form a suitable base for the level I El.

When this has been completed vial holders 30 in the form of insertable rings carrying one or more leveling fluid-containing vials I9, 20 are inserted into the openings I5 and secured conventionally as by screws 3| to the abutments I8. The latter are arranged with respect to the various openings I5 so that the vials I9 in some openings I5 are substantially parallel with the longitudinal axis of the level and in others are at degrees therewith or at any other desirable angles. When the rings 3| have been secured as described, annular Washers or rings. 32

of aluminum or other material, are applied to overlie the abutments I8 and conceal the joints between the latter and rings 30. Transparent cover plates 33 of glass or other suitable material are then applied over the rings 32 and these cover plates 33 are secured in place by resilient, split spring or snap retaining rings 34 preferably of steel which are deformable suiciently to permit their insertion within the annular flanges I5, I1 overlying the plates 33 at their rims. These spring retaining rings 34 engage frictionally with the inner walls of flanges I6 and I7 and hold the plates 33 securely in place on opposite sides of the vials I9, 20. They may be removed readily if necessary for the replacement of parts. It will be seen that the vials I9, 20, their rings 30, and the transparent cover plates 33 are exclusively and securely held in place within the metallic elements I2. They are nowhere in contact with wooden parts.

The combined metallic internal ply or core II and external wooden plies or layers 2l, 22 produce a structure which has high resistance to wear on the working edges because the center of the working edge is a metallic edge formed by the edges of the flanges of the metallic cores I2, I3. The structure is of reduced weight in comparison with an al1 metal level because its core only is of metal. faces is so firmly bonded to the metal core that the possibility of warping is eliminated. The structure is highly resistant to breakage or deformation. The metal core II would not break if the instrument fell but might tend tobend. However, the wood facing is very resistant to elongation and since it is so firmly bonded to the metal core on opposite faces any bending tendency of the core would require elongation of the wood on one face and compression on the other face. The Wood would resist such action and, therefore, prevent bending of the core and consequent deformation of the level. A tough durable level, therefore, is produced by the structure described.

Suitable bonding material for joining the wood and metal cores is of course necessary. In practice, bonding materials of resinous nature have been found to be most suitable. The resin used most successfully for coating of the metal surfaceof core I2, I3 is a product formed of a DuPont adhesive known as J-58-0027 (4653) and a DuPont catalyst known as JC-100-X- 6858. The resin applied asia rst or undercoat to the inner surfaces of the wooden plies 2I 22 isa Plywood product known as Pliobond Plastic Adhesive. other types of bonding agents that produce strong bonds when subjected to heat and pressure and which are resistant to atmospheric changes can, of course, be used.

Likewise the specic manner of mounting the Other suitable resinous or The Wood on the side spirit containing vials I9, 20 may be modified or changed. In addition, if desired, the metallic core segments I2, I3 may be formed initially as integral units of desired length. These segments preferably are of cast aluminum but other suitable metals Inay be used for their production.

Various other modifications in structure or material may be made and are contemplated. There is no intention of limitation to the exact details shown and described.

What is claimed is:

A level of the character described comprising a metallic core having substantially I beam setion and having longitudinally extending ribs on its opposite side faces, said eore having an open= ing extending transversely between said oppdi site side faces, annular, lateral, oppositelyextending flanges integral with said core positioned around said opening, abutments integral with said core and extending inwardly of said opening, wooden facing plies having inner surfaces complemental in shape to the side faces of said metallic core, said plies being adhesively bonded parmanently one to each opposite side face of said metallic core, said plies being coextensive with said side faces with their peripheral edges lying flush with corresponding peripheral edges of said metallic core, said plies each having an opening aligned with the opening in said metallic core into each of which one of the oppositely-extending flanges of said core rits, spirit vial supporting means positioned entirely in the opening in said metallic core, .and securing means for attaching said spirit vial supporting means to said abutments of said core.

THEODORE F. VAIDA.

REFERENCES CITED The following references are of record in the ille of this patent:

UNITED STATES PATENTS Number Name Date 44,225 Shepardson Sept. 13, 1864 436,495 Fox Sept. 16, 1890 623,492 Stimpson Apr. 18, 1899 759,899 Lynch May 17, 1904 1,201,617 Paschall Oct. 17, 1916 1,435,365 Zieman Nov. 14, 1922 1,552,371 Williams Sept. 1, 1925 1,690,053 Charlton Oct. 30, 1928 1,847,412 Petree Mar. 1, 1932 2,117,085 Ensminger May 10, 1938 2,118,470 Melvin May 24, 1938 2,127,617 Petree Aug. 23, 1938 2,241,312 Luty May 6, 1941 2,401,987 Taylor et al June 11, 1946 OTHER REFERENCES Wood-To-Metal Adhesives, by T. D. Perry. on pages 21, 22, 24 and 68 of Plastics, July 1947. 

